diff --git a/interpreter/cling/lib/Interpreter/CIFactory.cpp b/interpreter/cling/lib/Interpreter/CIFactory.cpp
index 179b34dfd6d15..f4c4ce8ef7693 100644
--- a/interpreter/cling/lib/Interpreter/CIFactory.cpp
+++ b/interpreter/cling/lib/Interpreter/CIFactory.cpp
@@ -49,7 +49,6 @@
   #define NOGDI
   #define NOMINMAX
   #include <Windows.h>
-  #include <sstream>
   #include <direct.h>
   #define popen _popen
   #define pclose _pclose
@@ -426,6 +425,13 @@ namespace {
         }
       }
 #else // _MSC_VER
+      // Skip LLVM_CXX execution if -nostdinc++ was provided.
+      for (const auto arg : args) {
+        if (!strcmp(arg, "-nostdinc++")) {
+          return;
+        }
+      }
+
       static const char *CppInclQuery =
         "echo | LC_ALL=C " LLVM_CXX " -xc++ -E -v - 2>&1 >/dev/null "
         "| awk '/^#include </,/^End of search"
diff --git a/interpreter/cling/lib/Interpreter/IncrementalExecutor.cpp b/interpreter/cling/lib/Interpreter/IncrementalExecutor.cpp
index e0cb86b8313c0..8a1dfda5c2ab2 100644
--- a/interpreter/cling/lib/Interpreter/IncrementalExecutor.cpp
+++ b/interpreter/cling/lib/Interpreter/IncrementalExecutor.cpp
@@ -43,7 +43,7 @@ using namespace llvm;
 
 namespace cling {
 
-IncrementalExecutor::IncrementalExecutor(clang::DiagnosticsEngine& diags):
+IncrementalExecutor::IncrementalExecutor(clang::DiagnosticsEngine& diags, const int& argc, const char* const *argv):
   m_CurrentAtExitModule(0)
 #if 0
   : m_Diags(diags)
@@ -57,14 +57,14 @@ IncrementalExecutor::IncrementalExecutor(clang::DiagnosticsEngine& diags):
   // can use this object yet.
   m_AtExitFuncs.reserve(256);
 
-  m_JIT.reset(new IncrementalJIT(*this, std::move(CreateHostTargetMachine())));
+  m_JIT.reset(new IncrementalJIT(*this, std::move(CreateHostTargetMachine(argc, argv))));
 }
 
 // Keep in source: ~unique_ptr<ClingJIT> needs ClingJIT
 IncrementalExecutor::~IncrementalExecutor() {}
 
 std::unique_ptr<TargetMachine>
-  IncrementalExecutor::CreateHostTargetMachine() const {
+  IncrementalExecutor::CreateHostTargetMachine(const int& argc, const char* const *argv) const {
   // TODO: make this configurable.
   Triple TheTriple(sys::getProcessTriple());
 #ifdef _WIN32
@@ -91,6 +91,28 @@ std::unique_ptr<TargetMachine>
   CodeModel::Model CMModel = CodeModel::JITDefault;
   CodeGenOpt::Level OptLevel = CodeGenOpt::Less;
 
+  for (int i = 0; i < argc; ++i) {
+    const std::string arg(argv[i]);
+    if (arg.length() != 3 || arg.rfind("-O", 0) != 0) {
+      continue;
+    }
+
+    switch (argv[i][2]) {
+      case '0':
+        OptLevel = CodeGenOpt::None;
+        break;
+      case '1':
+        OptLevel = CodeGenOpt::Less;
+        break;
+      case '2':
+        OptLevel = CodeGenOpt::Default;
+        break;
+      case '3':
+        OptLevel = CodeGenOpt::Aggressive;
+        break;
+    }
+  }
+
   std::unique_ptr<TargetMachine> TM;
   TM.reset(TheTarget->createTargetMachine(TheTriple.getTriple(),
                                           MCPU, FeaturesStr,
diff --git a/interpreter/cling/lib/Interpreter/IncrementalExecutor.h b/interpreter/cling/lib/Interpreter/IncrementalExecutor.h
index d594b05e965c9..a9ca106f95ec6 100644
--- a/interpreter/cling/lib/Interpreter/IncrementalExecutor.h
+++ b/interpreter/cling/lib/Interpreter/IncrementalExecutor.h
@@ -127,7 +127,7 @@ namespace cling {
     clang::DiagnosticsEngine& m_Diags;
 #endif
 
-    std::unique_ptr<llvm::TargetMachine> CreateHostTargetMachine() const;
+    std::unique_ptr<llvm::TargetMachine> CreateHostTargetMachine(const int& argc, const char* const *argv) const;
 
   public:
     enum ExecutionResult {
@@ -137,7 +137,7 @@ namespace cling {
       kNumExeResults
     };
 
-    IncrementalExecutor(clang::DiagnosticsEngine& diags);
+    IncrementalExecutor(clang::DiagnosticsEngine& diags, const int& argc, const char* const *argv);
 
     ~IncrementalExecutor();
 
diff --git a/interpreter/cling/lib/Interpreter/Interpreter.cpp b/interpreter/cling/lib/Interpreter/Interpreter.cpp
index c7a518fe4a12d..b16a153754091 100644
--- a/interpreter/cling/lib/Interpreter/Interpreter.cpp
+++ b/interpreter/cling/lib/Interpreter/Interpreter.cpp
@@ -193,7 +193,7 @@ namespace cling {
                                                      /*isTemp*/true), this));
 
     if (!isInSyntaxOnlyMode())
-      m_Executor.reset(new IncrementalExecutor(SemaRef.Diags));
+      m_Executor.reset(new IncrementalExecutor(SemaRef.Diags, argc, argv));
 
     // Tell the diagnostic client that we are entering file parsing mode.
     DiagnosticConsumer& DClient = getCI()->getDiagnosticClient();